From cfa367d7f9dfc36149ad5ad7a0ce8ab91e323e8c Mon Sep 17 00:00:00 2001
From: Wesley Wigham <wewigham@microsoft.com>
Date: Thu, 21 Nov 2019 13:13:46 -0800
Subject: [PATCH] Have definite assignment assertions on property signatures
 mark them as typescript (#35270)

---
 src/compiler/binder.ts                                   | 2 +-
 .../definiteAssignmentWithErrorStillStripped.errors.txt  | 9 +++++++++
 .../definiteAssignmentWithErrorStillStripped.js          | 9 +++++++++
 .../definiteAssignmentWithErrorStillStripped.symbols     | 7 +++++++
 .../definiteAssignmentWithErrorStillStripped.types       | 7 +++++++
 .../compiler/definiteAssignmentWithErrorStillStripped.ts | 5 +++++
 6 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/definiteAssignmentWithErrorStillStripped.errors.txt
 create mode 100644 tests/baselines/reference/definiteAssignmentWithErrorStillStripped.js
 create mode 100644 tests/baselines/reference/definiteAssignmentWithErrorStillStripped.symbols
 create mode 100644 tests/baselines/reference/definiteAssignmentWithErrorStillStripped.types
 create mode 100644 tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index a6c576e3a4..e09fa73e3c 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -3643,7 +3643,7 @@ namespace ts {
         let transformFlags = subtreeFlags | TransformFlags.ContainsClassFields;
 
         // Decorators, TypeScript-specific modifiers, and type annotations are TypeScript syntax.
-        if (some(node.decorators) || hasModifier(node, ModifierFlags.TypeScriptModifier) || node.type || node.questionToken) {
+        if (some(node.decorators) || hasModifier(node, ModifierFlags.TypeScriptModifier) || node.type || node.questionToken || node.exclamationToken) {
             transformFlags |= TransformFlags.AssertTypeScript;
         }
 
diff --git a/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.errors.txt b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.errors.txt
new file mode 100644
index 0000000000..d6625904b2
--- /dev/null
+++ b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.errors.txt
@@ -0,0 +1,9 @@
+tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts(2,6): error TS1255: A definite assignment assertion '!' is not permitted in this context.
+
+
+==== tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts (1 errors) ====
+    class C {
+        p!;
+         ~
+!!! error TS1255: A definite assignment assertion '!' is not permitted in this context.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.js b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.js
new file mode 100644
index 0000000000..2c397b83d8
--- /dev/null
+++ b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.js
@@ -0,0 +1,9 @@
+//// [definiteAssignmentWithErrorStillStripped.ts]
+class C {
+    p!;
+}
+
+//// [definiteAssignmentWithErrorStillStripped.js]
+class C {
+    p;
+}
diff --git a/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.symbols b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.symbols
new file mode 100644
index 0000000000..63a6f56b36
--- /dev/null
+++ b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts ===
+class C {
+>C : Symbol(C, Decl(definiteAssignmentWithErrorStillStripped.ts, 0, 0))
+
+    p!;
+>p : Symbol(C.p, Decl(definiteAssignmentWithErrorStillStripped.ts, 0, 9))
+}
diff --git a/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.types b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.types
new file mode 100644
index 0000000000..9cdd939ec3
--- /dev/null
+++ b/tests/baselines/reference/definiteAssignmentWithErrorStillStripped.types
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts ===
+class C {
+>C : C
+
+    p!;
+>p : any
+}
diff --git a/tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts b/tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts
new file mode 100644
index 0000000000..4f7f594363
--- /dev/null
+++ b/tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts
@@ -0,0 +1,5 @@
+// @target: esnext
+// @useDefineForClassFields: true
+class C {
+    p!;
+}
\ No newline at end of file